Astronauts will benefit from the use of 3D printing in the new Z-series spacesuit created for survival on Mars.
One of the most recognizable tech wearables, the spacesuit, is being redesigned and 3D printing is helping the development process.
Amy Ross, NASA's leading designer for the Z-series spacesuits, delivered the opening keynote address at the Ubicomp and ISWC 2014 conference in Seattle on Monday. She's spearheading the first total redesign of the prototype Mark III since it debuted in 1982.
"Spacesuits, why do you have to have them? Because you would be dead without them," Ross said during the keynote. Ross provided details of the Z-2 spacesuit, the follow-up to the earlier Z-1 spacesuit that she also designed. 3D scanning and printing is a significant step in the development of the Z-2. A sub-contractor was used for the 3D work. "We used Solid Concepts in Austin Texas. The process used was Selective Laser Sintering (SLS) with Glass filled Nylon 12," Ross said.
The Z-1 spacesuit has been compared to the suit worn by Buzz Lightyear in "Toy Story" because of its white and green accented design. The next in the series, the Z-2, was originally expected to be ready for testing in November this year, but it has been delayed until spring 2015. And the third version in the series, aptly named the Z-3, is already going to feature some changes based on what Ross has learned in early tests with the Z-2 spacesuit, she said in a separate interview.
"We know some requirements that will be needed for Z-3 that aren't included in Z-2. As you're working toward a higher fidelity suit we could only pay for and include a certain number of requirements," Ross explained. The contract for the Z-2 suit design is valued at $4.4 million, and was originally slated for 16 months, but will take longer, Ross said. "I told them it would take longer in the beginning but they didn't believe me."
Final delivery for the spacesuit and the all-important human-rated thermal vacuum chamber test will be 2018 or 2019. The process is time consuming because of all of the testing required before a component can be certified. Ross said that it took 2-1/2 years to certify just the Phase VI glove that flies on the ISS EMU now.
Mars as the baseline for design
The Z-2 suit is a planetary walking suit also designed for use in microgravity environments. It features a pressurized design with layers that can be inflated until taut. As a planetary suit, it fulfills different needs than what might be required on the space shuttle, or on space stations. But it can be modified to suit other purposes. Ross is designing it so that it will allow astronauts to walk on the surface of Mars, which is used as the baseline for the suit. A spacesuit that works on the extreme conditions found on the surface of the red planet can be modified for other uses.
"In a lot of ways a Mars mission is the most challenging in that it's a long mission, 540 days. A long time in microgravity transit. And there's the dusty environment. The chemical environment. And UV and some of the temperatures can be cold. We also look at other missions that we might be required to perform. And if Mars doesn't capture the most challenging element, we include that," Ross said.
The Z-2 suit represents a combination of all of the accumulated knowledge from 20 years of suit prototypes and mobility joint concepts that she's worked on. It's also the highest fidelity space suit since the shuttle Extravehicular Mobility Units (EMU). A high fidelity spacesuit can withstand impact. "If you fall down on Mars, we don't want your spacesuit to crack open and kill you," she said.
The spacesuit will also include electroluminescent wire and light-emitting patches to give a sporty look to the suit. That part of the design was voted on by the public in April as part of a public engagement effort. Ross said the next in the series, the Z-3 suit, will not include a public vote.
The biggest difference between the Z-1 and the Z-2 suit is that the Z-1 had a soft upper torso and the Z-2 has a hard composite upper torso. The hard composite resin adds long-term durability as needed in an Extravehicular Activity (EVA) suit. The shoulder joint differs significantly from the Z-1 suit, and is based on the Mark III design. The hip includes small changes made to improve performance. The resin is also changing, Ross said.
"We're making a new composite using some of the newer materials available. The resin we selected looked like it would work, but when we built the more complex components the resin didn't work. It's basically a sandwich of two different fabrics with the resin," Ross explained.
The Z-2 suit will feature:
- Hard upper torso - Used for advanced interfaces and structure, used on EMU and Mark II suits.
- Shoulder - External Link Rolling Convolute shoulder, previously used on ZPS and Mark III suits.
- Waist - Rolling Convolute waist, previously used on Mark III suit.
- Hip - Two bearing hip with ad/ab convolute used to create a natural gait, previously used on Z-1 suit.
- Boots - Wolverine over-boot with dual adjustable indexing features.
3D printing in spacesuit design
The Z-2 will be the first suit design with the help of 3D printing, Ross said.
By printing the upper torso of the suit, the team was able to determine that the shoulder to crotch distance was too long. "We'd made assumptions about how the humans would want it, but we were wrong. We had to shorten the torso based on actual human feedback about the fit," she said. Multiple 3D scans were made of the potential wearers of the spacesuit, in multiple positions, to allow the team to create a mockup for fit checks.
Ross is also working toward developing motion-tracking tools in real time to include wearable tech sensors placed on the torsos and arms and hands of test models to find out how a person would interface with the suit, such as points of contact that might rub and cause friction injuries, as well as determining the precise part of the arm that might be moving in order to lift the arm of the spacesuit.
"We already have some information from a recent test that says when a human moves their wrist, they move it about 30% more than the spacesuit moves," Ross said. That can cause fatigue in an astronaut, so Ross is working to design the suit to be easier to move around.
Using sensor and motion-tracking technology will give Ross an advantage over what designers had to work with in the past. "It's huge how that human interacts with that technology and how the suit interacts with that human," she said.
While Ross isn't technically working yet on the Z-3 prototype, since she must first complete the Z-2, she is already stashing away information as to what will need to change on the next iteration. "We want to incorporate an actual control unit on Z-3, the follow up to Z-2. We want to find some new types of tools to interact with the suit controls. Helmet mounted displays have been tested in the lab and the field with mixed results," she said.
But there is still more that that Ross wants in a spacesuit. She told the keynote audience of approximately 500 people that she invites their suggestions and, after showing a slide of Robert Downey Jr. as Iron Man, she said, "I want Iron Man. I want a true heads-up display. Augmented reality, that kind of thing. I want it out of the way when you don't need it, and there when you need it. I want it to function flawlessly."